66 lines
2.4 KiB
Python
66 lines
2.4 KiB
Python
import torch
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import torch.nn as nn
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import torch.optim as optim
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import torch.nn.functional as F
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from torchvision import transforms, datasets
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train = datasets.MNIST('./datasets', train=True, download=True,
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transform=transforms.Compose([
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transforms.ToTensor()
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]))
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test = datasets.MNIST('./datasets', train=False, download=True,
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transform=transforms.Compose([
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transforms.ToTensor()
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]))
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trainset = torch.utils.data.DataLoader(train, batch_size=10, shuffle=True)
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testset = torch.utils.data.DataLoader(test, batch_size=10, shuffle=False)
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class Net(nn.Module):
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def __init__(self):
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super().__init__()
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self.fc1 = nn.Linear(28 * 28, 64)
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self.fc2 = nn.Linear(64, 120)
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self.fc3 = nn.Linear(120, 120)
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self.fc4 = nn.Linear(120, 64)
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self.fc5 = nn.Linear(64, 10)
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def forward(self, x):
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x = F.relu(self.fc1(x))
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x = F.relu(self.fc2(x))
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x = F.relu(self.fc3(x))
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x = F.relu(self.fc4(x))
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x = self.fc5(x)
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return F.log_softmax(x, dim=1)
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net = Net()
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loss_function = nn.CrossEntropyLoss()
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optimizer = optim.Adam(net.parameters(), lr=0.001)
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for epoch in range(10): # 3 full passes over the data
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for data in trainset: # `data` is a batch of data
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X, y = data # X is the batch of features, y is the batch of targets.
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net.zero_grad() # sets gradients to 0 before loss calc. You will do this likely every step.
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output = net(X.view(-1, 784)) # pass in the reshaped batch (recall they are 28x28 atm)
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loss = F.nll_loss(output, y) # calc and grab the loss value
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loss.backward() # apply this loss backwards thru the network's parameters
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optimizer.step() # attempt to optimize weights to account for loss/gradients
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print(loss) # print loss. We hope loss (a measure of wrong-ness) declines!
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torch.save(net, './nets/net_' + str(epoch) + ".pt")
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correct = 0
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total = 0
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with torch.no_grad():
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for data in testset:
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X, y = data
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output = net(X.view(-1, 784))
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# print(output)
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for idx, i in enumerate(output):
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# print(torch.argmax(i), y[idx])
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if torch.argmax(i) == y[idx]:
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correct += 1
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total += 1
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print("Accuracy: ", round(correct / total, 3))
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